Ref. No. 1026/41-194
In the name of Allah the most Gracious the most Merciful
The answer to your question is as follows:
If she wakes up and finds wetness while she is sure that it is not mani (sperm) rather she is sure enough that it is leucorrhoea or pre-seminal fluid then she is not obliged to do Ghusl. She should make wadhu and perform Namaz.
And Allah knows best
Darul Uloom Waqf Deoband